2,796 research outputs found

    Calculations of spin-disorder resistivity from first principles

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    Spin-disorder resistivity of Fe and Ni is studied using the noncollinear density functional theory. The Landauer conductance is averaged over random disorder configurations and fitted to Ohm's law. The distribution function is approximated by the mean-field theory. The dependence of spin-disorder resistivity on magnetization in Fe is found to be in excellent agreement with the results for the isotropic s-d model. In the fully disordered state, spin-disorder resistivity for Fe is close to experiment, while for fcc Ni it exceeds the experimental value by a factor of 2.3. This result indicates strong magnetic short-range order in Ni at the Curie temperature.Comment: 3 pages, 3 figure

    Electric Current Tuning the Self-Oscillation Frequency of EC-VCSELs

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    The anatomy of the tympanic sinus

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    The tympanic sinus is one of the most important structures of the human temporal bone. Located in its vicinity are the round window, posterior semicircular canal and facial nerve. The study was performed on 30 temporal bones taken from adult cadavers of both sexes. After the tympanic sinus had been identified, its morphological features were evaluated. The sinus was then measured using a graticule with an accuracy of 0.05 mm. Also measured were the shortest distances from the tympanic sinus to the neighbouring structures (the lateral and posterior semicircular canal, the facial nerve canal and the jugular fossa). The measurements were performed under a surgical microscope with eye-piece graduation of 0.05 mm accuracy. Four main morphological types of fossa of the tympanic sinus and two main developmental forms, a deep sinus and a shallow sinus, were distinguished. The existence of a deep sinus was associated with absence of the bridge and the sinus was shallower when the bridge was prominent. The very deep sinuses were located close to the facial canal, in some cases penetrating deep in its vicinity (in some cases even going beyond two thirds of the canal’s circumference), which poses a real risk of facial nerve damage during surgical removal of a lesion located in close proximity to the nerve. In most cases the tympanic sinus is elliptical in shape and its long diameter lies in the vertical plane (mean value: 2.73 × 2.23 mm). The mean distances from the tympanic sinus to the facial nerve canal, lateral semicircular canal, posterior semicircular canal and jugular fossa were 1.5 mm, 2.1 mm, 1.59 mm and 5.5 mm respectively. No correlation was observed between the measurement results and either sex or side

    Pediatric Psychologists’ Career Satisfaction: 2015 Society of Pediatric Psychology Workforce Survey Results.

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    Little is known about the career satisfaction of pediatric psychologists, who specialize in psychological research, teaching, and clinical service in the context of pediatric health care. As part of the larger Society of Pediatric Psychology Workforce Survey and in collaboration with the American Psychological Association Center for Workforce Studies, this study aimed to (1) describe the career domains which pediatric psychologists perceive to be important and their satisfaction in each domain, and (2) compare satisfaction of pediatric psychologists across work settings, number of positions, appointment duration, professional roles, career stage, academic rank, and gender. Responses from 336 pediatric psychologists demonstrated high career satisfaction. Domains of career satisfaction that received mean scores indicating high importance include balance of work and personal lives, peer/collegial support, and flexibility and choice in the workplace, but on average respondents reported being only somewhat satisfied in these domains. Total satisfaction scores were significantly higher among pediatric psychologists in 9–10-month appointments, primarily research careers, and at higher academic ranks, but scores were similar across employment settings and genders. To enhance career satisfaction and retention, pediatric psychologists may seek additional mentorship or explore new employment roles, and administrators and managers may consider adopting workplace policies or making environmental changes that could address specific areas of need

    Type 1 diabetes in very young children: a model of parent and child influences on management and outcomes

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135479/1/pedi12351.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135479/2/pedi12351_am.pd

    Spin-density fluctuations and the fluctuation-dissipation theorem in 3d ferromagnetic metals

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    Spatial and time scales of spin density fluctuations (SDF) were analyzed in 3d ferromagnets using ab initio linear response calculations of complete wavevector and energy dependence of the dynamic spin susceptibility tensor. We demonstrate that SDF are spread continuously over the entire Brillouin zone and while majority of them reside within the 3d bandwidth, a significant amount comes from much higher energies. A validity of the adiabatic approximation in spin dynamics is discussed. The SDF spectrum is shown to have two main constituents: a minor low-energy spin wave contribution and a much larger high-energy component from more localized excitations. Using the fluctuation-dissipation theorem (FDT), the on-site spin correlator (SC) and the related effective fluctuating moment were properly evaluated and their universal dependence on the 3d band population is further discussed

    PHENIX first measurement of the J/psi elliptic flow parameter v2 in Au+Au collisions at sqrt(sNN) = 200 GeV

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    Recent results indicate that the J/psi suppression pattern differs with rapidity showing a larger suppression at forward rapidity. J/psi suppression mechanisms based on energy density (such as color screening, interaction with co-movers, etc.) predict the opposite trend. On the other hand, it is expected that more c\bar{c} pairs should be available to form quarkonia at mid-rapidity via recombination. Some models provide a way to differentiate J/psi production from initially produced c\bar{c} pairs and final state recombination of uncorrelated pairs, via the rapidity and transverse momentum dependence of the elliptic flow (v2). During 2007 data taking at RHIC, a large sample of Au+Au collisions at sqrt(sNN)=200 GeV was collected. The statistics has been increased compared to previous 2004 data set, thus allowing a more precise measurement of the J/psi production at both mid and forward rapidity. Furthermore, the PHENIX experiment benefited from the addition of a new detector, which improves the reaction plane resolution and allows us to measure the J/psi v2. Comparing this measurement to the positive D-mesons v2 (through non-photonic electron decays) will help constraining the J/psi production mechanisms and getting a more precise picture of the proportion of J/psi coming from direct production or charm quark coalescence. Details on how the J/psi v2 is measured at both rapidities are presented. The J/psi v2 as a function of transverse momentum are compared to existing models.Comment: 4 pages, 3 figures, Quark Matter 2008 proceeding

    Benefit finding among parents of young children with type 1 diabetes

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    Benefit finding, perceived positive effects of adversity, has been associated with psychological well‐being in people with chronic illnesses and with better adherence for adolescents with type 1 diabetes (T1D). Our qualitative research with parents of young children (< 6 years old) with T1D indicated that benefit finding (BF) is a common parental coping mechanism, but no tools exist to measure BF in parents. We determined psychometric properties of the Diabetes Benefit Finding Scale for Parents (DBFS‐P), a 16‐item questionnaire adapted from the validated adolescent version. Parents of young children with T1D (n = 172) were participants in a randomized trial of an online intervention. We examined the DBFS‐P factor structure through principal component analysis (PCA); internal consistency through Cronbach’s alpha; convergent validity via bivariate correlations between the DBFS‐P and measures of parental depression, anxiety, T1D self‐efficacy, and hypoglycemia fear; and discriminant validity via bivariate correlations between the DBFS‐P and measures of parental somatization and child behavior problems. PCA revealed one factor (56.47% variance) with Cronbach’s α = 0.95. Convergent validity of the DBFS‐P was supported by significant correlations with parental depression (r = −0.35, P < 0.001), anxiety (r = −0.20, P = 0.008), T1D self‐efficacy (r = 0.36, P < 0.001), and hypoglycemia fear (r = 0.27, P < 0.001). Non‐significant correlations with parental somatization (r = −0.06, P = 0.42) and child behavior problems (r = −0.12, P = 0.14) support its discriminant validity. The DBFS‐P demonstrated good psychometric properties as a tool for assessing BF among caregivers.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150510/1/pedi12860_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150510/2/pedi12860.pd
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